October 22, 2009
by Vince Stricherz

(PhysOrg.com) -- Researchers at the University of Washington and the University of North Carolina at Chapel Hill have taken an important step in converting methane gas to a liquid, potentially making it more useful as a fuel and as a source for making other chemicals.

Methane, the primary component of natural gas, is plentiful and is an attractive fuel and raw material for chemicals because it is more efficient than oil, produces less pollution and could serve as a practical substitute for petroleum-based fuels until renewable fuels are widely useable and available.

However, methane is difficult and costly to transport because it remains a gas at temperatures and pressures typical on the Earth's surface.

Now UNC and UW scientists have moved closer to devising a way to convert methane to methanol or other liquids that can easily be transported, especially from the remote sites where methane is often found. The finding is published in the Oct. 23 issue of the journal Science.

Methane is valued for its high-energy carbon-hydrogen bonds, which consist of a carbon atom bound to four hydrogen atoms. The gas does not react easily with other materials and so it is most often simply burned as fuel. Burning breaks all four hydrogen-carbon bonds and produces carbon dioxide and water, said Karen Goldberg, a UW chemistry professor.

Converting methane into useful chemicals, including readily transported liquids, currently requires high temperatures and a lot of energy. Catalysts that turn methane into other chemicals at lower temperatures have been discovered, but they have proven to be too slow, too inefficient or too expensive for industrial applications, Goldberg said.

Binding methane to a metal catalyst is the first step required to selectively break just one of the carbon-hydrogen bonds in the process of converting the gas to methanol or another liquid. In their paper, the researchers describe the first observation of a metal complex (a compound consisting of a central metal atom connected to surrounding atoms or molecules) that binds methane in solution. This compound serves as a model for other possible methane complexes. In the complex, the methane's carbon-hydrogen bonds remained intact as they bound to a rare metal called rhodium.

The work should spur further advances in developing catalysts to transform methane into methanol or other liquids, Goldberg said, although she noted that actually developing a process and being able to convert the gas into a liquid chemical at reasonable temperatures still is likely some distance in the future.

"The idea is to turn methane into a liquid in which you preserve most of the carbon-hydrogen bonds so that you can still have all that energy," she said. "This gives us a clue as to what the first interaction between methane and metal must look like."

Maurice Brookhart, a UNC chemistry professor, said carbon-hydrogen bonds are very strong and hard to break, but in methane complexes breaking the carbon-hydrogen bond becomes easier.

"The next step is to use knowledge gained from this discovery to formulate other complexes and conditions that will allow us to catalytically replace one hydrogen atom on methane with other atoms and produce liquid chemicals such as methanol," Brookhart said.

Titan's second most abundant constituent, methane, is critical to the maintenance of an earth-like nitrogen atmosphere on this satellite. Without methane, Titan's nitrogen would condense, leaving behind a puny amount in ...

(PhysOrg.com) -- A tiny microbe can take electricity and directly convert carbon dioxide and water to methane, producing a portable energy source with a potentially neutral carbon footprint, according to a team of Penn State ...

An abundant greenhouse gas could someday help clean up the earth. Converting methane to liquid methanol could produce clean, low-cost fuel and prevent the potent greenhouse gas from entering the atmosphere. Exploiting methane ...

Recommended for you

When life on Earth began nearly 4 billion years ago, long before humans, dinosaurs or even the earliest single-celled forms of life roamed, it may have started as a hiccup rather than a roar: small, simple molecular building ...

Using a hybrid silica sol-gel material and self-assembled monolayers of a common fatty acid, researchers have developed a new capacitor dielectric material that provides an electrical energy storage capacity rivaling certain ...

Virginia Commonwealth University and University of Richmond researchers recently teamed up to explore the inner workings of cells and shed light on the 400–600 million years of evolution between humans and early animals ...

(Phys.org)—A team of researchers at the Pennsylvania State University has created a new polymer that is able to store energy at higher temperatures than conventional polymers without breaking down. In their paper published ...

1 comment

I believe there is a Zeolite that Mobile Oil pioneered that does the following: Mobile built a plant in New Zealand and made gasoline out of methanol with the zeolite (which acts as a catalyst). Gasoline is much more useful than methanol. They used natural gas (methane) to make the methanol. If this catalyst can make methanol cheaply, then we will have a nice way to make gasoline from local stocks of methane.

Please sign in to add a comment.
Registration is free, and takes less than a minute.
Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.